TEHRAN, Feb. 18 (Xinhua) — An Iranian passenger plane crashed into the Dena mountain on Sunday morning and all the 66 people on board were killed, the spokesman for the Iranian Aviation Organisation said.

The report on Sunday says the plane crashed near the remote mountain town of Semirom, some 620 kilometers, or about 390 miles) south of the capital, Tehran.

The report identified the plane as an ATR-72. It said the plane was flying from Tehran to the southern Iranian city of Yasuj.

Under decades of international sanctions, Iran's commercial passenger aircraft fleet has aged, with air accidents occurring regularly in recent years.

Following the 2015 landmark nuclear deal with world powers, Iran signed deals with both Airbus and Boeing to buy scores of passenger planes.